Thread cutting device



1936- M. J. CLABBY ET AL THREAD CUTTING DEVICE 3 Sheets-Sheet 1 FiledOct. 21, 1935 INVENTORI' 1936- M. J. CLABBY ET AL THREAD CUTTING DEVICEFiled Oct. 21, 1953 s Sheets-Sheet 2 ATTORNEYS.

Nov. 10, 1936. M. J. CLABBY ET AL 2,060,609

THREAD CUTT I NG DEVICE Filed Oct. 21, 1953 3 Sheets-Sheet 3 INVENTORI'ATTORNEYS.

Patented Nov. 10, 1936 UNITED STATES A'iNT OFFICE THREAD CUTTING DEVICEApplication October 21, 1933, Serial No. 694,610

Claims.

This invention relates to a new and improved thread-cutting device, forcutting a thread in a pipe or other article.

One of the objects of the invention is to provide a new and improvedholder for the thread-cutting device so that the same can be easily andconveniently inserted into and removed from its holder.

Another object of the invention is to provide the device with animproved holder for the thread-cutting die or dies so that there will bea limited relative movement between said threadcutting device (ordevices) and the holder.

Another object of the invention is to provide a holder for thethread-cutting device, in which the holder shall have a single movablepart for holding or maintaining the thread-cutting device (or devices)in the holder.

Another object of the invention is to provide an improved ratchet-drivefor said holder, so that the ratchet-drive can be conveniently andreliably adjusted in orderto drive the holder in the forward or in thereverse direction, and said ratchet drive can be adjusted so that it isrendered inoperative.

Another object of the invention is to provide the device with animproved adjustable guide for guiding the movement of said device uponthe pipe or the like.

Another object of the invention is to provide a guide which consists ofinner and outer shells which are relatively turnable, the inner shellhaving cam slots and the outer shell having concentric slots, the outershell also having openings in which there are located the pivot pins ofa plurality of cam members, said cam members being provided withadditional pins or lugs which are located in said cam slots.

Other objects of my invention will be set forth in the followingdescription and drawings which illustrate certain preferred embodimentsthereof, it being understood that the above general statement of theobjects of my invention is intended merely to generally explain the sameand not to limit it in any manner.

Fig. 1 is a top plan view of the improved device, showing thethread-cutting device in its operative position.

Fig. 2 is a side elevation of Fig. 1.

Fig. 3 is a bottom plan view of the device shown in Fig. 1.

Fig. 4.- is a detail elevation, taken in the direction of the arrows ofthe line 4-4 of Fig. 1,

Fig. 5 illustrates another embodiment of the invention.

Fig. 6 is a side elevation of Fig. 5.

Fig. 7 is a plan view illustrating the ratchetdrive, the drive beingshown in the inoperative position in this view.

Fig. 8 is a diagrammatic view showing one of 5 the ratchet-drive arms,in the operative position.

Fig. 9 is a view similar to Fig. 8 showing the other ratchet-drive armin its operative position.

Fig. 10 is a detail plan view of the adjustable guide which forms partof the device. 10

Fig. 11 is a detail View illustrating the connection between theadjustable guide, and the holder for the thread-cutting device.

For convenience, the device may be described as being held in thehorizontal position, although 15 it may be operated in any position.

Referring to Fig. 1, the device comprises a ratchet-drive having ahollow member I, into Whose end socket an operating member 2 can beinserted. The ratchet-drive member l is provided with a regulatingmember 3 which is provided with a pivot pin 4 and a finger hold 5. Stoppins 9 and 6a are provided, and the finger hold 5 abuts either one ofsaid stop pins in the respective operative positions of theratchetdrive. One of these positions corresponds to the forward movementof the ratchet-drive, and the other position corresponds to the reversemovement of the ratchet-drive.

In the position shown in Fig. 1, the ratchetdrive is inoperative so thatthe device can be quickly removed from the pipe or other article whichhas been threaded. The respective positions of the finger hold 5 areindicated by the lines I and 1a,.

The device is provided with a thread-cutting device and an improvedadjustable guide for the pipe, rod, or other object which is to bethreaded.

Referring to Fig. 4, the thread-cutting device has a holder 3, having aflange 9 which is provided with teeth In, having intermediate recessesH. The member I is provided with a suitable socket i2, which fits overthe flange 9 of the holder 8. The holder 8 is provided with a shoulderit, against which an edge of said socket l2 abuts, when the device isassembled. When the device is assembled, the inner ends of the teeth H3are substantially flush with the adjacent edge of the socket 12. Themember I is therefore provided with a suitable bearing upon the holder8, and

said member I can be turned to and fro upon said holder 8.

Referring to Fig. 7, the hollow member I is provided with a pair of armsl5 and I50, which are pivotally connected to said member I by means of apivot pin IS. A tension spring H is connected to the operating arms [5and 1511, so as to produce a scissor-like closing movement of said arms15 and Hill.

As shown in Figs. 8 and 9, the pivot pin 4, which turns in unison withthe member 3, is provided with a cam !3 which has a flat face 19. Whensaid cam is held in the position shown in Fig. 7, the operating ends ofthe arms i5 and Mia are held spaced from the recesses l i so that themembar I can be turned without operating the holder 8. When the fiatface I9 is in the position shown in Fig. 8, the arm 15a is in theoperative position and the arm I5 is in the inoperative position.

Referring to Fig. 8. when the cam i8 is in the position there shown, themember i can be turned in the counter-clockwise direction, and the arm15a then slips over the teeth I9 so that the holder 3 remains idle. Whenthe member i is turned in the clockwise direction, the arm lilo causesthe simultaneous turning movement of the holder 8.

Referring to Fig. 9, when the cam 98 is in the position shown therein,the member I can be turned relative to the holder 8 in the clockwisedirection, and the members and 8 turn in unison when the member I isturned in the counterclockwise direction.

Referring to the embodiment shown in Figs. 1, 2 and 4, the holder 8 isprovided with upstanding lugs 29 and 29:1, having the top flanges 2i and2 la and having equal and parallel and planar faces 22 and 22a, saidfaces 22 and 2212. being perpendicular to the bottom faces of the lipsor flanges 2| and Zia.

Referring to Fig. 1 the holder is also provided with a lug 23, having aplanar face. When the thread-cutting device or die D is placed upon thetop of the holder 8, it may fit loosely in said holder 8. However,instead of having a relative movement between the die D and the holder8, the die D may be held immovable relative to said holder 8.

A certain limited relative movement between the die D and the holder 8is often desirable, in order to permit the die D to shift so as to beaccurately centered with respect to the work. If there is relativelateral movement between the die D and the holder 8, said relativemovement is limited in one direction by the upstanding planar face ofthe lip 23. Said relative movement in another lateral direction is alsolimited by the accurately ground planar faces 22 and 22a. Relativelongitudinal movement is limited by the accurately ground planar facesprovided at the bottoms of the lips 2| and 2 la. This longitudinalmovement is in excess of the normal clearance which is provided in orderto enable the die D to be slid into and out of the holder.

Referring to Figs. 1 and 4, the die D can be retained in the holder 8,while permitting relative movement between said die and said holder, bymeans of a retaining member 24, which is turnably connected to theadjacent face 25 of the holder 8, said face 25 being preferably planar.The retaining member 24 is provided with a knurled finger-hold 26. Inthe position shown in Fig. 4, the retaining member 24 is in theoperative position, and its flat face 24a abuts a stop pin 21, so that apart of said retaining member 24 projects above that face of the holder8, upon which the die D rests. When the member 25 is turned in thecounter-clockwise direction, its fiat face is brought to the upperposition, so that the die D can be either inserted or removed.

Any suitable retaining member or members, such as a set screw or screws,can be utilized for clamping the die D to the holder 8, in order toprevent relative movement between them. The retaining devicespecifically illustrated in Figs. 1 and 4 permits a limited relativemovement of the die D with respect to the holder 8, in a directionperpendicular to the axis of said holder 8, and also in a directionparallel to said axis. If desired, the members 28 and 28a could bedimensioned so as to permit little or no relative movement of the die Drelative to the holder 8, in a direction parallel to the axis of saidholder, while permitting a relative movement in a directionperpendicular to said axis. Likewise the distance between the faces 22and 22a may exceed the correspondingdimension of the die D, as shown inFig. 4, so as to permit the die D to have a limited turning movementabout the axis of the holder 8. The movement of the die D relative tothe holder 8 can therefore be regulated in any desired manner, bysuitably dimensioning the parts, and if desired, the die D can be heldimmovable in the holder 8.

Referring to Fig. 2, the top of the lug 23 is below the bottoms of theplanar faces 22 and 22a. Hence the device can be accurately shaped bymeans of a suitable revolving mill of cylindrical shape. This mill canbe passed through the holder 8 so as to grind the planar faces 22 and22a, and to also accurately grind the bottom faces of the lips 25 andZia. Assuming that the holder is held in the horizontal position shownin Fig. 2 and in Fig. 4, said revolving mill may be mounted upon avertical shaft, and said vertical shaft may be moved in a horizontaldirection, so that the mill can simultaneously shape the above mentionedfaces, while permitting the bottom face of said cylindrical mill toclear the top of the lip 23. Any suitable milling or grinding tool canbe used for this purpose.

While I have shown an integral thread-cutting device or die D, having asquare shape, the device can be shaped so as to receive a die oftriangular or any other desired shape and the invention also applies toa thread-cutting device made of a plurality of parts.

Referring to Fig. 5, this shows a modified provided with a flange 36,into which box-like holder So having a top box-like part which is partthe die D is dropped by a tilting movement. The top of said holder 8a isprovided with a lug 3|, and said lug has an overhanging flange, as shownin Fig. 6, in order to limit the vertical movement of the die D relativeto the holder 8a Said lug also has a vertical planar face adjacent tothe bottom planar face of said flange.

A retaining member 32 is turnably connected to the holder 8a and saidretaining member 32 has a fiat face 3312, which abuts a stop pin 34. Inthe position shown in Fig. 5, the retaining member 32 prevents theremoval of the die D. When said member 32 is turned in thecounterclockwise direction, its flat face 33 is moved to a positionwhich permits the removal of the die D. In the embodiment shown in Figs.5 and 6, there may be the same limited relative movement or movementsbetween the thread-cutting device and the holder, as in the embodimentpreviously described.

If desired, the member 32 can clamp the die D to the holder, and theholder can be dimensicned so as to tightly hold the die D.

The underside of the member I has an adjustable guide G connectedthereto for the work piece which is to be threaded.

Referring to Fig. 7 and Fig. 11, the member 9 is provided withinternally threaded holes 35, there being any desired number of suchholes.

The guide G is provided with an outer shell 36, and an inner shell 31.The inner shell 31 is provided with holes 35a, which register with theholes 35, when the device is assembled.

Referring to Fig. 11, the walls of the holes 35a are provided withshoulders 38, against which the heads of the screws 39 abut, when saidscrews are turned to their final position. The shell 31 is provided withlugs 4| having internally threaded holes. The outer shell 36 is providedwith concentric slots 42, and the shanks of screws 43 pass through saidslots and engage the internally threaded openings of the lugs 4| Theheads of the screws 43 are slightly spaced from the outer shell 36 inorder to permit a limited gurmng movement of the shell 36, relative toshell The shell 36 is provided with cam members C and said cam members Care provided with pins 45 which move in cam slots 46, which are providedin said inner shell 31. Said cam members 0 are also provided with pivotpins 41, which pass through suitable openings which are provided in theouter shell 36.

Hence, when the outer shell is turned relative to the inner shell, saidcam members C are turned about their pivot pins 41, so that they projectmore or less within the central openings which are provided in saidshells. Said gripping cam members C slidably engage the pipe or otherworkpiece, so that the guide is made adjustable for difi'erent sizes ofpipe or the like.

A set screw 46 has its shank passing through an internally threaded lugof the outer shell 36, in order to prevent any relative movement betweenthe shells 36 and 31, after the cams C have been adjusted.

The above mentioned construction of the adjustable guide diminishes itsbulk and minimizes any binding of the relatively turnable shells 36 and31.

Referring to the ratchet-drive, the fiat face E9 of the cam i8 causessaid cam to be reliably held in the positions shown in Fig. 7 and Fig.8.

The invention is not necessarily limited to the mounting of the arms I 5and lfia' upon a single pivot as the improved cam Hi can be utilizedwith arms which are mounted upon separate pivots.

Likewise, while a complete combined tool has been illustrated, in orderto show the complete combination, it is obvious that the elements ofsaid tool comprise valuable and independent subcombinations which can beused independently of the complete combination which has beenillustrated.

Referring to Figs. 1, 4 and 5, the flange 30 is generally equivalent tothe members 20 and 20a. and 23, in limiting the movement of thethread-cutting means in a lateral direction. The member 3| and themembers 2| and 2Ia of Fig. 4 limit the movement of the thread-cuttingmeans relative to the holder, in a direction parallel to the axis of theholder. In both said embodiments, said retaining means prevent theremoval of the thread-cutting means, save along a predetermined line ofmovement, which includes the tilting movement which is required towithdraw the die D from the embodiment shown in Fig. 5. In both saidembodiments there is a movable retaining member which prevents theremoval of the thread-cutting means along said predetermined line.

When we refer to limiting the movement of the thread-cutting meansrelative to the holder, it is to be understood that we include thelocking of the thread-cutting means within the holder, so as to preventany relative movement between the holder and the thread-cutting means.

For example while we have shown a cam [8 having a flat face Hi, theinvention is not limited to the use of a flat face, as we could use amutilated face which may be convex, and even slightly concave.

It is preferable to have the mutilated face of the cam correspond incontour to the adjacent portions of the ratchet-drive arms.

Referring to Figs. 3, 6 and 10, the shanks of the screws 43 may beprovided with shoulders, so, as to limit the entrance of said shanks,into the lugs 4|. These shoulders positively cause the heads of saidscrews to be spaced from the outer shell 36, thus preventing any bindingbetween the shells 31 and 36. The shoulders of said screws 43 can abutthe adjacent lateral faces of the lugs 4|. We have shown a preferredembodiment of our invention, but it is clear that numerous changes andomissions can be made without departing from its spirit.

We claim:

1. In a thread-cutting device, a holder adapted to have thread-cuttingmeans located therein, said holder having a pair of upstanding lugshaving lips which overlie and are spaced from said thread-cutting means,said holder also having a third lug intermediate the first mentionedlugs, said first mentioned lugs having upstanding ground faces and saidlips having bottom ground faces, the bottoms of said upstanding groundfaces being above the top of the third lug, the thread-cutting devicehaving faces which correspond to and which are spaced from the adjacentfaces of said three lugs, said holder having a holding device which isadapted to retain said thread-cutting means loosely in position betweensaid lugs, said holding device being spaced from said thread-cuttingmeans when the holding device is in operative position, the holderhaving teeth adapted to be engaged by the pawls of a ratchet-operatingdevice.

2. A thread-cutting device comprising a holder, thread-cutting meansmovable into and out of said holder, retaining means adapted to retainsaid thread-cutting means in said holder, while permitting a limitedrelative movement between said thread-cutting means and said holder in adirection perpendicular to the axis of said threadcutting means, andmovable holding means adapted to prevent the removal of saidthreadcutting means from said holder, said movable holding means beingspaced from the thread-cutting means when said holding means are in theoperative position, so as to permit said relative movement of thethread-cutting means, the clearance between said thread-cutting meansand said retaining means being in excess of the clear ance which isrequired to insert and to withdraw said thread-cutting means, saidholder having teeth adapted to be engaged by the pawls of aratchet-operating device.

3. In a thread-cutting device, a holder having teeth adapted to beengaged by the pawls of a ratchet-operating device, said holder having aplurality of upstanding lugs between which a thread-cutting device canbe located, a movable holding device connected to said holder andadapted to retain said thread-cutting device between said lugs, saidholding device being spaced from the thread-cutting device when theholding device is in the operative position, said threadcutting devicebeing movable relative to the holder in a direction perpendicular to theaxis of the holder, the clearance between said thread-cutting device andsaid lugs being greater than the normal clearance which is required toinsert said thread-cutting device in position.

4. In a thread-cutting device, a hollow ratchetdrive member having asocket into which the toothed end of a holder for a thread-cuttingdevice can be fitted, said member having a pair of pivoted armsconnected thereto, spring means adapted to force the ends of said armsinto engagement with the teeth of said toothed end, said member having aturnable cam located between said arms, said cam having flat face, botharms contacting with said cam in all positions of said cam, each armbeing in the operative position when it contacts with the flat face ofsaid cam, both arms being held in the inoperative position when neitherarm contacts with the fiat face of the cam.

5. A thread-cutting device comprising a holder having teeth which areadapted to be engaged by the pawls of a ratchet-operating device, saidholder having a pair of upstanding lugs which are provided with parallelplanar faces which are parallel to the axis of the holder, said lugshaving inwardly extending lips at their tops, the top of said holderhaving a third lug which is located between the previously-mentionedlugs, said third lug having an inner planar face which is parallel tosaid axis and which is perpendicular to the planar faces of thepreviously mentioned lugs, a thread-cutting device having an outerperiphery of rectangular cross-section and slidable into position sothat three of the faces of said holder are adjacent the planar faces ofsaid three lugs, and a movable holding device adapted to retain saidthread-cutting device in position between said lugs, said holding devicebeing spaced from said thread-cutting device when the holding device isin operative position, said thread-cutting device being movable relativeto said lugs in a direction perpendicular to the axis of the holder, theclearance between the threadcutting device and said lugs being greaterthan the normal clearance which is required for permitting the holder tobe inserted into position between the lugs.

HARRY S. ASHMUN. MICHAEL J CLABBY.

